Biscayne National Park weather in August

August in Biscayne National Park: sweltering, soaked, with clean air — not the time — 17 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Biscayne National Park🇺🇸 United States · Florida · National park46
  1. 81Jan
  2. 79Feb
  3. 78Mar
  4. 72Apr
  5. 62May
  6. 52Jun
  7. 51Jul
  8. 46Aug
  9. 48Sep
  10. 59Oct
  11. 68Nov
  12. 75Dec

#12 of 12 months in Biscayne National Park · #1262 of 1413 destinations to visit in August · comfort 46/100 (tier F)

Days
33°C
Nights
27°C
Wet days
17
Sun
10.6 h
Humidity
81%
Daylight
13 h
Biscayne National Park, United States
Photo: Catholic 85 at English Wikipedia · CC BY-SA 3.0

Traveller notes on Biscayne National Park in August

Other months in Biscayne National Park

Biscayne-forum threads on a February visit describe boat transport to Elliott Key as genuinely available for around sixty dollars from the visitor center, posters naming this a standard option for reaching the islands. Regulars call February weather genuinely capable of turning rough, several posters warning reaching the outer reef for snorkeling can be unreliable. Posters call a park-authorized private operator genuinely the safer bet, several regulars naming this the recommended workaround when conditions make independent boating harder. Regulars call guided sail or powerboat trips a real standard way to see the park, several threads naming island stops, paddling and snorkeling at Maritime Heritage Trail shipwrecks as included on half and full-day options. Posters recommend a guided trip over independent boating in February, several regulars calling this standard given how much conditions vary. The record: 26.6C days, 19.6C nights, 47.2mm across 5 days and 75 percent humidity.
BiscayneFebruaryRegular · February · 1 month ago · Read more on tripadvisor.com.ph ↗
Biscayne-forum threads on an April visit describe conditions as calm and pleasant, one couple describing a six-hour sail, paddle and snorkel tour on the last day of April with a knowledgeable captain as a highlight of their Florida trip. Regulars call April part of the park's spring window, several posters noting calmer seas than summer make it a real favorite for kayaking and paddleboarding. Posters recommend booking a boat, kayak or snorkel tour well ahead this time of year, regulars calling spring the busiest stretch and warning popular slots fill fast. Regulars call ninety-five percent of the park water, several posters repeating that skipping a boat or paddling component means missing the best of what Biscayne offers. Posters recommend real sunscreen and a hat regardless of a mild-feeling morning, April sun here considered strong enough to catch first-timers off guard. The record: 29.1C days feeling like 31C, 22.5C nights, 73.4mm across nearly 7 days and 72 percent humidity.
BiscayneAprilRegular · April · 1 month ago · Read more on Tripadvisor ↗
Biscayne National Park-forum threads on a December visit call getting out on the water genuinely essential here, posters recommending kayaking, a boat trip to Boca Chita Key or a visit to Stiltsville as the real ways to experience the park. Regulars call the Biscayne National Park Institute's two main tours, the Boca Chita Island Experience and a boat tour including Stiltsville, solid options for anyone without their own boat. Posters call winter genuinely the tougher season for reef snorkeling here, conditions typically requiring a private authorized operator rather than a casual outing. Regulars call the visitor center and its walking trail worth a stop regardless of water plans, a real orientation before heading out. Posters recommend checking current tour schedules directly, December capacity varying by operator. The record: 26.4C days feeling like 27C, 19.3C nights, 62.4mm across nearly 7 days and 71 percent humidity.
BiscayneDecemberRegular · December · 1 month ago · Read more on Tripadvisor ↗
Biscayne-forum threads on snorkeling advice describe conditions as genuinely improving through November, the wetter, stormier stretch easing off toward the more favored December-through-April window. Posters call reef and wreck snorkeling trips weather-dependent regardless of season, operators adjusting plans on the day rather than canceling outright. Regulars describe access to the park as almost entirely by boat, the small visitor center and a short coastal trail the only parts reachable without a tour. Posters recommend booking a snorkeling or boat tour through the authorized park institute rather than arranging anything independently. Regulars call water clarity generally strong once the wetter pattern eases, a real upside of visiting later in the month. Posters recommend checking current conditions the morning of any scheduled water activity. The record: 28.2C days feeling like 30C, 21.5C nights, an extraordinarily high 95mm across nearly 8 days and 77 percent humidity.
BiscayneNovemberRegular · November · 1 month ago · Read more on Tripadvisor ↗

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Biscayne National Park climate normals — August

Daytime high33°C / 91°F🔥 sweltering
Nighttime low27°C / 80°F
Feels like (high)39°C / 102°F
Sea temperature32°C / 89°F♨️ bath-warm
Rainfall176 mm / 6.9 in⛈ soaked
Rainy days17 days
Humidity81%💦 very humid
Dew point24°C / 76°F
Sunshine10.6 h/day
Daylight13 h
Wind17 km/h / 11 mph
Air quality (US AQI)39🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Biscayne National Park in August

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Peak crowdsSpiny lobster season, Summer break in United States, school holidays in 2 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Biscayne National Park's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Toughest weatherBiscayne National Park's weather peaks January–March.

August coincides with Mosquitoes on the keys.

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Best weatherFair weatherToughest weather

What's on in Biscayne National Park in August

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Hazard

    Mosquitoes on the keys

    15 Apr – 30 Nov · usuallyInsects & disease

    Once the winter breezes drop, mosquitoes swarm in the hardwood forest on Elliott and Boca Chita keys, worst from May through August; the water is fine, but island trails and camping are hard going without long sleeves and repellent. Source ↗

  • Hazard

    Atlantic hurricane season

    1 Jun – 30 Nov

    Ninety-five per cent of this park is water, so a storm three days out closes everything with an engine long before it arrives. Mid-August to mid-October is the busy stretch; the rest of the season is mostly afternoon thunder. Source ↗

  • Season

    Spiny lobster season

    6 Aug – 31 MarForaging seasonCrowded

    The regular season runs from August into spring, and the two-day sport season on the last Wednesday and Thursday of July fills the bay with boats. Harvest is banned year-round in the park's five coral reef protection areas. Source ↗

What's on around the world in August →

Nearby, and something's on

Within 300 km of Biscayne National Park — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Biscayne National Park?

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Biscayne National Park in August — FAQ

Is August a good time to visit Biscayne National Park?
August in Biscayne National Park: sweltering, soaked, with clean air — not the time — 17 rainy days. It ranks #12 of 12 months for Biscayne National Park on SeasonMap's comfort score (46/100).
What is the weather like in Biscayne National Park in August?
In August, Biscayne National Park averages a daily high of 32.5°C and a low of 26.7°C, with about 176.3 mm of rain over roughly 16.6 rainy days.
What is the air quality in Biscayne National Park in August?
Biscayne National Park has a mean US Air Quality Index of about 39 in August.

Within 300 km: Miami's Sea turtle nesting on 1 Mar – 31 Oct, and Fort Lauderdale's Sea turtle nesting on 1 Mar – 31 Oct.